SEGMENT INFORMATION - Geographical (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) segment	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Long Lived Assets and Pre-Tax Income by Geographical Information
Number of reportable segments | segment			2
Total stream and royalty interests, net	$ 3,053,988		$ 3,053,988		$ 3,075,574
Revenue	174,096	$ 144,042	322,999	$ 314,434
Cost of sales	24,174	23,367	45,924	48,387
Production taxes	1,581	1,274	3,031	3,263
Depletion	35,658	38,297	74,341	84,512
Segment gross profit	112,683	81,104	199,703	178,272
Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	1,102,521		1,102,521		1,076,298
Dominican Republic
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	306,692		306,692		311,050
Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	249,391		249,391		264,850
Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	440,901		440,901		446,745
United States
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	783,860		783,860		794,891
Mexico
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	36,903		36,903		41,803
Australia
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	20,437		20,437		21,288
Rest of world
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	113,283		113,283		118,649
Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	1,299,194		1,299,194		1,351,616
Revenue	122,952	106,015	225,481	221,005
Cost of sales	24,174	23,367	45,924	48,387
Production taxes	0	0	0	0
Depletion	26,124	29,352	53,525	63,104
Segment gross profit	72,654	53,296	126,032	109,514
Stream interest | Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	439,843		439,843		461,398
Revenue	62,661	50,848	107,365	107,829
Stream interest | Dominican Republic
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	306,692		306,692		311,050
Revenue	19,801	23,540	37,562	45,899
Stream interest | Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	249,070		249,070		264,529
Revenue	20,396	18,763	39,497	36,301
Stream interest | Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	216,785		216,785		222,629
Revenue	10,608	7,823	22,297	20,757
Stream interest | United States
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	0		0		0
Stream interest | Mexico
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	0		0		0
Stream interest | Australia
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	0		0		0
Stream interest | Rest of world
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	86,804		86,804		92,010
Revenue	9,486	5,041	18,760	10,219
Royalty revenue:
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	1,754,794		1,754,794		1,723,958
Revenue	51,144	38,027	97,518	93,429
Cost of sales	0	0	0	0
Production taxes	1,581	1,274	3,031	3,263
Depletion	9,534	8,945	20,816	21,408
Segment gross profit	40,029	27,808	73,671	68,758
Royalty revenue: | Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	662,678		662,678		614,900
Revenue	3,035	(97)	8,166	6,495
Royalty revenue: | Dominican Republic
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	0		0		0
Royalty revenue: | Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	321		321		321
Royalty revenue: | Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	224,116		224,116		224,116
Royalty revenue: | United States
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	783,860		783,860		794,891
Revenue	25,273	23,265	49,352	56,845
Royalty revenue: | Mexico
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	36,903		36,903		41,803
Revenue	12,888	8,155	23,656	17,449
Royalty revenue: | Australia
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	20,437		20,437		21,288
Revenue	7,047	5,081	12,022	9,180
Royalty revenue: | Rest of world
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	26,479		26,479		$ 26,639
Revenue	$ 2,901	$ 1,623	$ 4,322	$ 3,460